Providing Grid applications with effective access to large volumes of data residing on a multitude of storage systems with very different characteristics prompted the introduction of storage resource managers (SRM). Their purpose is to provide consistent and efficient wide-area access to storage resources unconstrained by their particular implementation (tape, large disk arrays, dispersed small disks). To assess their viability in the context of the US Atlas Tier 1 facility at Brookhaven, two implementations of SRM were tested: dCache (FNAL/DESY joint project) and HRM/DRM (NERSC Berkeley). Both systems included a connection to the local HPSS mass data store providing Grid access to the main tape repository. In addition, dCache offered storage aggregation of dispersed small disks (local drives on computing farm nodes). An overview of our experience with both systems will be presented, including details about configurations, performance, inter-site transfers, interoperability and limitations.